code: def test_empty_array(self):
      named_array.NamedNumpyArray([], [None, ["a", "b"]])
      with self.assertRaises(ValueError):
          # Must be the right length.
          named_array.NamedNumpyArray([], [["a", "b"]])
      with self.assertRaises(ValueError):
          # Returning an empty slice is not supported, and it's not clear how or
          # even if it should be supported.
          named_array.NamedNumpyArray([], [["a", "b"], None])
      with self.assertRaises(ValueError):
          # Scalar arrays are unsupported.
          named_array.NamedNumpyArray(1, [])
  
imports: import collections
  import enum
  import pickle
  from absl.testing import absltest
  from absl.testing import parameterized
  import numpy
  from pysc2.lib import named_array
label_desc: Use image node_id 4 for calling the NamedArrayTest obj's underlying member method code with example usage: obj.test_empty_array() without return types